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Asked: 2026-05-11T14:30:36+00:00

I realized that i was using a varchar attribute as a index/key in a

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I realized that i was using a varchar attribute as a index/key in a query, and that is killing my query performance. I am trying to look in my precienct table and get the integer ID, and then update my record in the household table with the new int FK, placed in a new column. this is the sql i have written thus far. but i am getting a

Error 1093 You can’t specify target table ‘voterfile_household’ for update in FROM clause, and i am not sure how to fix it.

UPDATE voterfile_household SET PrecID = (SELECT voterfile_precienct.ID         FROM voterfile_precienct INNER JOIN voterfile_household         WHERE voterfile_precienct.PREC_ID = voterfile_household.Precnum);
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  1. Try:

    update voterfile_household h, voterfile_precienct p    set h.PrecID = p.ID  where p.PREC_ID = h.Precnum

    Take a look at update reference here.

    Similarly, you can use inner join syntax as well.

    update voterfile_household h inner join voterfile_precienct p on (h.Precnum = p.PREC_id)    set h.PrecID = p.ID
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